1. Field of the Invention
The present invention relates in general to the field of electrical assist of traditionally human powered vehicles, e.g., bicycles, scooters, etc. More particularly, the present invention relates to bicycles equipped with a braking system that utilizes brake rotors and calipers. Specifically, the present invention relates to retrofitting electric assist to pedal-powered bicycles that use brake rotors and calipers.
2. Discussion of the Related Art
Riding bicycles is a popular pastime for physical exercise as well as a means of transportation. In an effort to promote the utilitarian benefits of bicycle riding, electric bicycles have become popular in recent times. Electric bicycles allow individuals to use the same bicycle to get physical exercise as well as a means of transportation while avoiding exhaustion. This may be done by allowing the operator to pedal as the sole means of propulsion, use an electric drive as the sole means of propulsion, or use the electric drive to assist the pedaling efforts of the operator. Electric bicycles supplement the riders pedaling motion to minimize fatigue, increase the distance the operator can travel, and provide a more relaxing means of transportation.
One drawback to electric bicycles is that they are considerably expensive. When the bicycle is designed from the ground up to incorporate electronic controls, an electric, motor, a battery pack, and the necessary hardware, it imposes a significant financial burden that many consumers are not willing to absorb. As a result, retrofitting existing bicycles with electric drives has become popular.
When retrofitting a bicycle with an electric drive, there are a number of possible locations to mount the electric equipment on the bicycle. One problem is that there is limited space available on a bicycle frame to accommodate the electric drive equipment. It is therefore desirable to minimize the components needed as well as minimize the required space needed for the electric drive. It is also desirable to improve existing electric bicycle retrofit packages by utilizing existing components of the pedal drive.
Another drawback to existing electric drive retrofits is that they utilize their own components to transfer the assisted power from the electric motor to the bicycle. For example, one popular retrofit uses a completely new rear wheel with an electric motor incorporated into the central hub of the wheel. This solution is typically very expensive and wheel damage is harder to repair as it is not a common “off the shelf” item. Other common electric retrofits add an electric motor to the bicycle frame and transfer power with a series of belts and/or chains. The added gear may be added directly to the crank or to the gears on the rear wheel. An added chain or belt is then used, providing additional weight, complexity, and maintenance to the bicycle.
What is therefore needed is an electric bicycle retrofit that utilizes existing components of the bicycle. What is also needed is a way to transfer the electric assist power to the bicycle without additional chains or gears. What is also needed is an improved electric retrofit that utilizes less space on the bicycle frame.